Anti-toppling furniture extension leg



Uni ed. State P te ANTI-TOPPLING FURNITURE EXTENSION LEG Victor H. Hiers and Claude G. Kanzelberger, Two Rivers, Wis., assignors to Hamilton Manufacturing Company, j Two Rivers, Wis., a corporation of Wisconsin Application September 16, 1957, Serial No. 684,056 r 3 Claims. (Cl. 4s 1s9 This invention relates to furniture extension leg more particularly for use withengineers desks, drafting tables and the like in such professional fields where adjustability of the height of the desk or table within relatively small ranges is desirable for the purpose for example of contributing to the comfort and efficiency of the engineer or draftsman and thereby enhancing his productive capacity.

Among other objects, the invention aims to provide a simple and economical structure of the class described which is readily adaptable, without change in design or manufacture, to different tables or desks and which can be readily manipulated by the owner or user to adjust the height of a piece of furniture from the floor, each such leg being identical with the other and being embodied in an operatively unitary device the operation of which may be achieved without the use of tools or instruments.

In an important aspect the invention contemplates telescoping leg parts suitably arranged for cooperative relationship with each other and with the supported article of furniture.

In another aspect, the invention contemplates abrace member that may be associated with means for extending the leg vertically and may be associated with vertically extensible parts of the leg for bracing the piece of furniture against toppling, where, for example, the piece of furniture may be a drafting table that in some adjustable position of the drafting board may be relatively high with respect to the area of its base, such brace being readily connected in operative position with the vertically extensible leg part.

These and other objects and advantages will be apparent from the following description, taken together with the accompanying drawing, showing an illustrative embodiment of the invention, and in which drawing- Figure 1 is an elevational view of an extension leg embodying the present invention associated with an article of furniture shown fragmentarily and showing in dotted lines a further vertically extended adjustment;

Figure 2 is an enlarged axial section of the extension leg of Fig. 1;

Figure 3 is another elevational view showing the brace member associated with the leg;

Figure 4 is a plan section on the line 44 of Fig. 3;

Figure 5 shows a modification; and

Figure 6 shows a detail of one form of connection between the leg and brace member, being a fragmentary axial section of the leg.

Referring in detail to the illustrative construction shown in the drawing, the numeral 11 may indicate a fragment or lower corner of a desk or cabinet, generally of the class hereinbefore referred to and commonly including a recess 12 for a purpose presently explained and to which the extension leg of the present invention is attached as next described.

In accordance with the present invention, the extension leg includes a hollow pedestal 13 that is here shown 2,931,128 Patented Apr. 5, 1960- comprising an outer metal tube 14 depending from a socket or T-nut 21 that has a depending flange 22 that is welded as at 23 to the centering plate 1 For cooperation with the hollow pedestal 13, theinvention contemplates a cylindrical plug 24 ,that is here shown comprising an inner tube 25 that snugly butslidably fits within the outer tube 14. At its lower end, the tube 25 carries a radially enlarged foot 26 that is centrally perforated to pass therethrough a headed bolt 28, the head 29 of which is received in a central counterbore 30 in the lower face of the plug foot 26.

At its upper end, the tube 25 carries a closure orcap 31 that is perforated centrally as at 32 to pass therethrough the shank of the bolt 28 which at its upper end is screwthreaded as at 33 to be threadedly received in the socket 21 carried by the pedestal 13. The bolt 28 is desirably threaded from adjacent the plug cap 31 to its upper end and has screwed thereon the nut 34 which is clampingly locked against the cap 31 to prevent rotation of the bolt 28 with respect to the plug 24. The recess 12 in the furniture 11 receives the tubular socket 21 as well as the upper end of the bolt 28 so as to prevent interference with the operation of the latter, into and out of the socket 21.

It will be manifest that rotation of the plug 24 with respect to the pedestal 13 will move the plug in or out, as the case may be, of the pedestal and will shortenor extend the overall length of the leg comprising the pedestal and plug jointly. For example, the plug may be moved from the position shown in full lines in Fig. l to that shown in broken lines indicating an extension of the leg for elevating the height of the table of which the fragment 11 is a part. The foot 26 not onlyserves' as a closure for the lower end of the plug and as a centering member for the bolt 28 but also limits inward movement of the plug with respect to the pedestal to a position in which the foot 26 is in abutment with the lower end of the pedestal, such being the maximum contracted condition of the leg. The maximum extended position of the leg would be one in which the bolt 28 is partially withdrawn from the threaded socket 21 but leaving suflicient interengagement of the bolt with the socket to prevent the plug from dropping out of the pedestal.

Further in accordance with the present invention, there is here shown associated with the extensible leg, thus far described, the brace member 35 which comprises a lower bracket element 36 and an upper bracket element 37. The lower bracket element 36 has a ring end or circular opening 38 therein that may snugly receive the tube part 25 of the plug 24 so that the lower bracket element 36 may be in abutment with the foot 26 of the plug. In this form the foot 26 prevents the bracket element 36 of the brace '35 from falling off the plug.

The upper bracket element 37 carries a crotch portion 37a at its inner, upper end that has an arcuate notch 39 therein that snugly but partially receives the tube 14 of the pedestal 13 in sliding engagement. Between the brace lower element 36 and upper element 37 the latter has a pair of tapered side walls 40 that act as strut elements between elements 36 and 37 and that lap the upturned edges 41 of the lower element 36 and are spot welded thereto as at 42. The upper element 37 slopes downwardly from its inner end to meet the lower also tapered element 36 as at 43. At their outer ends, where the elements 36 and 37 converge they may be secured together-as by welding, and apad44 issecuredv on the. lower face of the element 36 by a rivet 45 that passes through both elements, the pad thus resting on the floor. As-seen byFigs. 3 and 4=the brace 35 is taperedinboth the'horizontaland vertical planes thereof.

-As the plug 24 isscrewedin or out of the pedestal 1 3- the; brace member 35 moves with the plug and moves relatively to pedestal 13, the latter sliding in the arcuate notch 39 of the brace. Thus the brace is always at the lower end of the leg'regardless of the extent to which the plug is withdrawn from or invaginated with the pedestal.

'-'In one form just described, where the ring 38 slips onto the tube 25, the brace '35 is free to rotate on a horizontal plane with the leg as a.pivot thus adapting itselr' to any lateral direction in which it is desired to place the brace, independently ofextension or contraction of'the leg, for the purpose of assistingand preventing any toppling action of the-furniture piece 11.

'In the construction shownin Fig. 5, which may :be thepreferred form, the ring 38a is shown having an internaldiameter to fit onto the reduced shank 26a of the foot 26 to which it is clamped by lower end of tube 725:: so that thetube 25a,'fo0t 26 and brace 35 turn together as a unit, the brace moving in a spiral path about the axis-of the leg. Thus for a given radial location of the brace member, the least vertical adjustment of the leg wouldbe the equivalent of one turn of the adjusting screw, or desirably not more than one-eighteenth inch, which is commerciallyacceptable.

ln'the modification of Fig.6, the mounting plate 15 is replaced by the mounting 100 that integrally incorporates a;centering member -1 in place of the disc 16, and an integral socket element 102 that takes the place of the T-nut 21 and isinternally threaded as at 103 to have the bolt 28 screwed thereinto, thussimplifying the construction.

.Bolt head 29 may manipulation.

.-Arc weld 14a is shown securing tube 14 to the mounting plate.

have kerf 29a :for :convenience of .It. mavnuthe eessentiaLthatralLfeaturespf theinvention be used conjointly and such changes or adaptations may be made as fall within the scope'of the appended claims without departing from the spirit thereof.

What is here claimed is:

1. In anti-toppling furniture extension leg arrangement for use with rotatably and vertically relatively movablecylindrical legmembers including a, lower member telescoped within the upper member and aninternal screw threaded connection therebetween, the lower member having an enlarged foot below the upper member, the combination therewith of a laterally extending brace device comprising a pair of upper and lower bracket elements and a vertical strut element, .said device being triangular in a vertical plane with its larger vertical dimension adjacent its inner end, said inner end being spaced from said leg elements to provide play therebetween, said upper gbra'cket element. sloping upwardly from thedevicesouterend to its inner end, azcircular rin -like extensiOn 1on saidrlower bracket element encirclingsaid lower. leg member; and resting on said-foot and "a 'partiecircular crotch-like extension on said upper bracket elemenhpartially encircling the said upper leg part, said extensions being vertically held apart by said strut element, said crotch-like extension having sliding vertical and rotative engagement with the upper leg member in movements ofthe lower leg member inwardly and outwardly of the upper leg member.

2. Thestructure of claim 1 wherein the brace is rigidly connectedto'the said lower leg memberto rotate therewith.

3. :The structureof claimil wherein the brace is relatively rotatable on the, lower leg member.

References Cited in the file of this patent UNITED-STATES PATENTS 272,390 Stimson, Feb. 13,1883 611,260 Larnoureux Sept. 27, 1,898 843,973 Taussig Feb. 12, 1907 2,535,613 Vanderbeek Dec. 26, 1950 

